1. Field of the Invention
The present invention relates to surgical drill guides and more particularly pertains to a new curved drill guide system for forming a channel in a vertebra of a patient for receiving a screw for screw fixation of a fracture.
2. Description of the Prior Art
The invention is directed to the treatment of fractures of the odontoid process from the body of the second cervical vertebra of a patient. The odontoid process is a tooth-like protrusion of bone extending upwardly from the body of the second cervical vertebra and it forms a pivoting joint with the first cervical vertebra for permitting the head of a person to rotate generally about the longitudinal axis of the body.
In particular, hyperflexion or hyperextension of the head can cause a type II odontoid fracture which generally occurs across the base of the odontoid process at the general location where the odontoid process meets the body of the second cervical vertebra.
One treatment of the type II fracture of the odontoid process involves anterior screw fixation, in which a channel is formed in a generally upward direction through an inferior surface of the second cervical vertebra and into the body of the second cervical vertebra, through the fracture line and into the odontoid process. Once the channel has been formed, the channel is tapped with threads and a screw is then threaded into the channel to secure the odontoid process to the body of the second cervical vertebra. One illustrative description of such a procedure is set forth by Ronald I. Apfelbaum, M.D. in ANTERIOR SCREW FIXATION OF ODONTOID FRACTURES, Neurological Operative Atlas, Vol. 2, No. 3, 1992, pages 189-199.
The channel has typically been formed using a rigid drill bit inserted through a straight drill guide extending through an anterior incision in the patient""s neck. However, using this apparatus for this surgical technique is difficult, if not impossible, in some patients, especially those that have very short necks, very large necks, or very prominent anterior chest walls. In these cases, the rigid drill bit with the straight drill guide cannot be oriented at a suitable angle for forming the channel through the body and odontoid process of the second cervical vertebra. Almost invariably, another treatment approach must then be utilized.
The curved drill guide system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of forming a channel in a vertebra of a patient for receiving a screw for screw fixation of a fracture.
In view of the foregoing disadvantages inherent in the known types of surgical drill guides now present in the prior art, the present invention provides a new curved drill guide system construction wherein the same can be utilized for forming a channel in a vertebra of a patient for receiving a screw for screw fixation of a fracture.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new curved drill guide system which has many of the advantages of the surgical drill guides of the prior art and many novel features that result in a new curved drill guide system.
The present invention generally comprises an elongate handle member for being held by the hand. A mounting aperture extends through the handle member, with the mounting aperture having an axis oriented perpendicular to a longitudinal axis of the handle member. A guide member is provided for removably receiving and guiding a flexible drill bit. The guide member comprises a guide tube adapted for removably inserting into the aperture of the handle member. The guide tube has a base end and a free end and a length therebetween. A bore extends along the length of the guide tube and open at the base and free ends. The guide tube has an arcuate shape, with the arcuate shape being substantially uniform along the length of the guide tube.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The various objects and features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.